spring boot 已经支持多数据源配置了,无需网上好多那些编写什么类的,特别麻烦,看看如下解决方案,官方的,放心!
1.首先定义数据源配置
#=====================multiple database config============================#ds1first.datasource.url=jdbc:mysql://localhost/test?characterEncoding=utf8&useSSL=truefirst.datasource.username=rootfirst.datasource.password=123456first.datasource.driver-class-name=com.mysql.jdbc.Driverfirst.datasource.type=org.apache.tomcat.jdbc.pool.DataSourcefirst.datasource.max-wait=10000first.datasource.max-active=200first.datasource.test-on-borrow=truefirst.datasource.initial-size=10 #ds2second.datasource.url=jdbc:mysql://localhost/test2?characterEncoding=utf8&useSSL=truesecond.datasource.username=rootsecond.datasource.password=123456second.datasource.driver-class-name=com.mysql.jdbc.Driversecond.datasource.type=org.apache.tomcat.jdbc.pool.DataSourcesecond.datasource.max-wait=10000second.datasource.max-active=200second.datasource.test-on-borrow=truesecond.datasource.initial-size=10
#=====================jpa config================================#实体类维护数据库表结构的具体行为:update/create/create-drop/validate/nonespring.jpa.hibernate.ddl-auto=none#打印sql语句spring.jpa.show-sql=true#格式化输出的json字符串spring.jackson.serialization.indent_output=true 2.配置ds1的相关注入对象和启用jpa支持
/** * Created by hdwang on 2017-06-16. * 第一个数据源配置 * If you are using Spring Data, you need to configure @EnableJpaRepositories */ @Configuration @EnableTransactionManagement @EnableJpaRepositories(basePackages = "com.hdwang.dao.datajpa.firstDs",entityManagerFactoryRef = "firstEntityManagerFactory",transactionManagerRef="firstTransactionManager") public class FirstDsConfig { /** * 数据源配置对象 * Primary 表示默认的对象,Autowire可注入,不是默认的得明确名称注入 * @return */ @Bean @Primary @ConfigurationProperties("first.datasource") public DataSourceProperties firstDataSourceProperties() { return new DataSourceProperties(); } /** * 数据源对象 * @return */ @Bean @Primary @ConfigurationProperties("first.datasource") public DataSource firstDataSource() { return firstDataSourceProperties().initializeDataSourceBuilder().build(); } /** * 实体管理对象 * @param builder 由spring注入这个对象,首先根据type注入(多个就取声明@Primary的对象),否则根据name注入 * @return */ @Bean @Primary public LocalContainerEntityManagerFactoryBean firstEntityManagerFactory( EntityManagerFactoryBuilder builder) { return builder .dataSource(firstDataSource()) .packages("com.hdwang.entity.dbFirst") .persistenceUnit("firstDs") .build(); } /** * 事务管理对象 * @return */ @Bean(name = "firstTransactionManager") @Primary public PlatformTransactionManager transactionManager(EntityManagerFactory emf){ JpaTransactionManager transactionManager = new JpaTransactionManager(); transactionManager.setEntityManagerFactory(emf); return transactionManager; } @Bean @Primary public JdbcTemplate jdbcTemplate(){ return new JdbcTemplate(firstDataSource()); } @Bean @Primary public TransactionTemplate transactionTemplate(PlatformTransactionManager platformTransactionManager){ return new TransactionTemplate(platformTransactionManager); } }
相关知识点:1.使用@Bean可以创建一个bean对象交给spring容器管理[email protected]创建的bean对象的名称默认为方法名,也可以指定[email protected]方法参数表示,接收一个bean对象,默认按照type类型接收注入的对象,若要修改为byName方式,可以使用@Qualifier注解注入准确的对象[email protected]表示该bean为此类型的默认bean,在其他地方引用的时候用@Autowired即可按照类型注入,不受同类型多个对象影响5.EnableJpaRepositories表示启用spring data jpa的支持,也就是jpa的新使用方式,注意basePackages指的事 @Repository接口的所在包位置,可配置多个其他注解就不清楚了!
2.配置ds2的相关注入对象和启用jpa支持
@Configuration @EnableTransactionManagement @EnableJpaRepositories(basePackages = "com.hdwang.dao.datajpa.secondDs", entityManagerFactoryRef = "secondEntityManagerFactory",transactionManagerRef = "secondTransactionManager") public class SecondDsConfig { @Bean @ConfigurationProperties("second.datasource") public DataSourceProperties secondDataSourceProperties() { return new DataSourceProperties(); } @Bean @ConfigurationProperties("second.datasource") public DataSource secondDataSource() { return secondDataSourceProperties().initializeDataSourceBuilder().build(); } /** * 实体管理对象 * @param builder 由spring注入这个对象,首先根据type注入(多个就取声明@Primary的对象),否则根据name注入 * @return */ @Bean public LocalContainerEntityManagerFactoryBean secondEntityManagerFactory( EntityManagerFactoryBuilder builder) { return builder .dataSource(secondDataSource()) .packages("com.hdwang.entity.dbSecond") .persistenceUnit("secondDs") .build(); } /** * 事物管理对象 * @param secondEntityManagerFactory 实体管理工厂对象(按照名称注入) * @return 平台事物管理器 */ @Bean(name = "secondTransactionManager") public PlatformTransactionManager transactionManager(@Qualifier("secondEntityManagerFactory")LocalContainerEntityManagerFactoryBean secondEntityManagerFactory){ JpaTransactionManager transactionManager = new JpaTransactionManager(); transactionManager.setEntityManagerFactory(secondEntityManagerFactory.getObject()); return transactionManager; } @Bean(name="jdbcTemplate2") public JdbcTemplate jdbcTemplate(){ return new JdbcTemplate(secondDataSource()); } @Bean(name = "transactionTemplate2") public TransactionTemplate transactionTemplate(@Qualifier("secondTransactionManager")PlatformTransactionManager transactionManager){ return new TransactionTemplate(transactionManager); } }
3.Repository数据持久层
package com.hdwang.dao.datajpa.firstDs; @Repository public interface UserRepository extends JpaRepository<User, Integer> { /** * spring data jpa 会自动注入实现(根据方法命名规范) * @return */ User findByNumber(String number); @Modifying @Query("delete from User u where u.id = :id") void deleteUser(@Param("id")int id); }
package com.hdwang.dao.datajpa.secondDs; @Repository public interface OrderRepository extends JpaRepository<Order, Integer> { /** * spring data jpa 会自动注入实现(根据方法命名规范) * @return */ User findByNumber(String number); @Modifying @Query("delete from Order o where o.id = :id") void deleteUser(@Param("id") int id); }
上面两个接口分属两个数据源,在@EnableJpaRepositories配置好后,这里就可以正确操作相应的数据源了 4.Service服务层,注意事物(接口我就不贴了)
@Service @Transactional("firstTransactionManager") public class UserServiceImpl implements UserService { @Autowired private UserRepository userRepository; @Override public User findById(int id) { return this.userRepository.findOne(id); } @Override public User findByNumber(String number) { return this.userRepository.findByNumber(number); } @Override public List<User> findAllUserByPage(int page,int size) { Pageable pageable = new PageRequest(page, size); Page<User> users = this.userRepository.findAll(pageable); return users.getContent(); } @Override public User updateUser(User user,boolean throwEx) { User userNew = this.userRepository.save(user); if(throwEx){ throw new RuntimeException("throw a ex"); } return userNew; } @Override public void deleteUser(int id) { this.userRepository.deleteUser(id); } }
@Service @Transactional("secondTransactionManager") public class OrderServiceImpl implements OrderService { @Autowired private OrderRepository orderRepository; @Override public Order findById(int id) { return this.orderRepository.findOne(id); } @Override public Order updateOrder(Order order, boolean throwEx) { Order orderNew = this.orderRepository.save(order); if(throwEx){ throw new RuntimeException("throw a ex"); } return orderNew; } }
知识扩展 1.如果采用传统jpa方式,@EnableJpaRepositories无需配置,配置了也无影响。实现方式如下: ds1相关DaoImpl
@PersistenceContextprivate EntityManager entityManager; ds2相关DaoImpl
@PersistenceContext(unitName = "secondDs")private EntityManager entityManager; 因为ds1的entityManger声明了@Primary,所以无需指明unitName,ds2必须指明。注入了准确的entityManager,就可以直接拿来操作数据库了。service层和上面一样的,@Transactional("xxxManager")指明事物管理器即可! 2.采用jdbcTemplate方式,直接注入到Service层对象即可,so easy!
@Autowiredprivate JdbcTemplate jdbcTemplate; @Autowiredprivate TransactionTemplate transactionTemplate; @Resource(name="jdbcTemplate2")private JdbcTemplate jdbcTemplate2; @Resource(name="transactionTemplate2")private TransactionTemplate transactionTemplate2; 好了,spring boot 多数据源,完美解决! 而且三种数据库操作方法均支持,包括事物。已经经过实践证明了! 这是官方给出的最佳实践,知识官方文档没写细。导致整整坑了我几天。至此,spring boot框架的使用就告一段落了!
时间: 2024-10-12 18:45:42